The amount of times a multi hit move hits is determined by accuracy, so if I had a Pokemon with a multi hit move (let's say Chesnaught with pin missile) used pin missile and hit 2 times. But then later it gets baton passed a +6 accuracy boost. If it uses pin missile again, will pin missile hit 5 times no matter what?
There is an exact percentage that determines how likely the move is going to hit 2, 3, 4 and 5 times, although Pokemon with Skill link will always hit 5 times.
This is how likely the moves will hit 2, 3, 4 or 5 times in a row.
Hope I helped. :]